Zoology and wildlife conservation

Rapid braincase evolution between Panderichthys and the earliest tetrapods

Article Abstract:

The braincase of the fish Panderichthys rhombolepis, a member of the Middle Devonian tetrapod stemgroup, has evolved faster than the external skull structure. The brain had an external structure that resembles tetrapods, but the braincase contained an intracranial joint resembling that of the lobe-finned fish. Thus, the braincase transformation appears to have taken place between Panderichthys and the earliest tetrapods. The changes in the braincase probably coincided with changes in the limbs during the evolution of tetrapods from fish.

Osteolepiforms and the ancestry of tetrapods

Article Abstract:

Progress in fossil discoveries has focused on the upper part of the Tetrapodomorpha, and there have been few advances in improving knowledge of the lower, fish part of the group. Central to the debate about tetrapod origins are the Osteolepiformes. A detailed analysis of the lower part of the Tetrapodomorpha is presented, showing that the Osteolepiformes are paraphyletic to tetrapods and their uniting characters are attributes of the tetrapodomorph stem lineage.

Elginerpeton pancheni and the earliest tetrapod clade

Article Abstract:

Examination of the cranial characters of Elginerpeton and Obruchevichthys reveals that both are the joint sister group to all other tetrapods. The derived head morphology of Elginerpeton indicates that a previously unrecognized morphological and phylogentic diversification accompanies the earliest state of tetrapod evolution. Significant divergence of the elginerpetontids from the tetrapod stem is reflected by their mode of life.